package cn.lee.cplibrary.util.encrypt.base64;

import java.security.KeyFactory;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;

/**
 * RSA签名验签类
 */
public class RSASignature
{

    /**
     * 签名算法
     */
    public static final String SIGN_ALGORITHMS = "SHA1WithRSA";

    /**
     * RSA签名
     * 
     * @param content 待签名数据
     * @param privateKey 商户私钥
     * @param encode 字符集编码
     * @return 签名值
     */
    public static String sign(String content, String privateKey, String encode)
    {
        try
        {
            PKCS8EncodedKeySpec priPKCS8 = new PKCS8EncodedKeySpec(Base64.decode(privateKey));

            KeyFactory keyf = KeyFactory.getInstance("RSA");
            PrivateKey priKey = keyf.generatePrivate(priPKCS8);

            java.security.Signature signature = java.security.Signature.getInstance(SIGN_ALGORITHMS);

            signature.initSign(priKey);
            signature.update(content.getBytes(encode));

            byte[] signed = signature.sign();

            return Base64.encode(signed);
        }
        catch (Exception e)
        {
            e.printStackTrace();
        }

        return null;
    }

    public static String sign(String content, String privateKey)
    {
        try
        {
            PKCS8EncodedKeySpec priPKCS8 = new PKCS8EncodedKeySpec(Base64.decode(privateKey));
            KeyFactory keyf = KeyFactory.getInstance("RSA");
            PrivateKey priKey = keyf.generatePrivate(priPKCS8);
            java.security.Signature signature = java.security.Signature.getInstance(SIGN_ALGORITHMS);
            signature.initSign(priKey);
            signature.update(content.getBytes());
            byte[] signed = signature.sign();
            return Base64.encode(signed);
        }
        catch (Exception e)
        {
            e.printStackTrace();
        }
        return null;
    }

    /**
     * RSA验签名检查
     * 
     * @param content 待签名数据
     * @param sign 签名值
     * @param publicKey 分配给开发商公钥
     * @param encode 字符集编码
     * @return 布尔值
     */
    public static boolean doCheck(String content, String sign, String publicKey, String encode)
    {
        try
        {
            KeyFactory keyFactory = KeyFactory.getInstance("RSA");
            byte[] encodedKey = Base64.decode(publicKey);
            PublicKey pubKey = keyFactory.generatePublic(new X509EncodedKeySpec(encodedKey));

            java.security.Signature signature = java.security.Signature.getInstance(SIGN_ALGORITHMS);

            signature.initVerify(pubKey);
            signature.update(content.getBytes(encode));

            boolean bverify = signature.verify(Base64.decode(sign));
            return bverify;

        }
        catch (Exception e)
        {
            e.printStackTrace();
        }

        return false;
    }

    public static boolean doCheck(String content, String sign, String publicKey)
    {
        try
        {
            KeyFactory keyFactory = KeyFactory.getInstance("RSA");
            byte[] encodedKey = Base64.decode(publicKey);
            PublicKey pubKey = keyFactory.generatePublic(new X509EncodedKeySpec(encodedKey));

            java.security.Signature signature = java.security.Signature.getInstance(SIGN_ALGORITHMS);

            signature.initVerify(pubKey);
            signature.update(content.getBytes());

            boolean bverify = signature.verify(Base64.decode(sign));
            return bverify;

        }
        catch (Exception e)
        {
            e.printStackTrace();
        }

        return false;
    }

}